+-
« previous next »
Pages: [1]   Go Down

Author Topic: Race Fuel Question  (Read 926 times)

Offline

  • Trade Count: (0)
  • Elite Member
  • **********
  • Posts: 2493
  • Gender: Male
  • Location: Cincinnati OH
Race Fuel Question
« on: January 23, 2013, 01:02:06 pm »
Gonna be running 100-110 octane race fuel my question is should it be leaded or unleaded is there a difference and also does oxygenated vs non oxygenated matter?
Logged

Share on Bluesky Share on Facebook

Offline

  • Trade Count: (0)
  • Range Rover
  • *****
  • Posts: 306
  • Gender: Male
  • Location: Central Mass
Re: Race Fuel Question
« Reply #1 on: January 23, 2013, 03:24:59 pm »
I was wondering the same about the leaded/unleaded.
Logged

Offline

  • Trade Count: (0)
  • Elite Member
  • **********
  • Posts: 2493
  • Gender: Male
  • Location: Cincinnati OH
Re: Race Fuel Question
« Reply #2 on: January 23, 2013, 03:46:49 pm »
I dealt with petroliums oils and lubricants in the Air Force so up would think I would know the answer to this. Should've paid better attention in fuel lab of course that was dealing with JP-8 which is nothing like gasoline.
Logged

Offline

  • Mitch Keller
  • Trade Count: (0)
  • Administrator
  • Trail Blazer
  • *****
  • Posts: 799
  • Love The Smell Of 927 and Race Fuel In The Morning
  • Location: Riverside Ca
Re: Race Fuel Question
« Reply #3 on: January 23, 2013, 03:59:40 pm »
I run Leaded Race Fuel due to I run 4 strokes also.
VP Racing Fuels, Inc—Race Fuel, Coolants, Fuel Additives, Racing Oil
VP Racing Fuels is your one-stop shop for premium race fuels, lubricants, coolants, fuel additives, octane boosters, small engine fuels, diesel care, and more.
VP Racing Fuels, Inc. · vpracingfuels.com
Logged
F Mitch Keller

Offline

  • Trade Count: (0)
  • Pro Member
  • ********
  • Posts: 858
Re: Race Fuel Question
« Reply #4 on: January 24, 2013, 08:02:57 am »
Quote from: Buckeye513 on January 23, 2013, 01:02:06 pm
Gonna be running 100-110 octane race fuel my question is should it be leaded or unleaded is there a difference and also does oxygenated vs non oxygenated matter?

100 octane leaded has the same detonation protection as 100 octane unleaded.  110 octane leaded has the same detonation protection as 110 octane unleaded.  The octane number is the fuels rating to resist detonation.  The leaded fuel is usually cheaper for the same octane than unleaded.

Leaded fuel is preferred in four-strokes to help provide high temperature valve seat lubrication.  It really does not matter which fuel you use in a two-stroke as long as the octane rating is high enough for your engine build. 

Oxygenated fuels require richer jetting and have the potential for slightly more power. 

Oxygenated fuels hurt rubber and plastic more rapidly. 

Osygenated fuels create more health related issues. 

Logged

Offline

  • Trade Count: (0)
  • Elite Member
  • **********
  • Posts: 2493
  • Gender: Male
  • Location: Cincinnati OH
Re: Race Fuel Question
« Reply #5 on: January 24, 2013, 08:47:04 am »
Thanks motorgeek so basically the only difference between 110 leaded and 110 unleaded is price no big performance difference. And I should go non oxygenated unless I'm running drags. Would I be better off running 100 leaded for trails and then running 110 leaded oxygenated for drag races? Or should I just consistently use say 110 leaded non oxygenated for all riding?
Logged

Offline

  • Trade Count: (0)
  • Range Rover
  • *****
  • Posts: 589
  • Gender: Male
  • If they can't kick start it--they cant ride it
  • Location: Utah
Re: Race Fuel Question
« Reply #6 on: January 24, 2013, 09:44:59 am »
My understanding is that your motor type size and  build and other variables but----most specifically compression ratio will determine the octane rating required to not allow it to detonate.  Higher octane does not mean the gas gives you more power. That is a myth.  A motor that is set up to run on 85 octane will not make any more power on 110 octane fuel.  However,  If that same motor had the compression bumped to require 110 octane it would make more power because of the compression increase and would there fore require the 110 fuel.  Try to run the 85 octane in the high compression motor and it would obviously make less power/ detonate/ and eventually you would have an expensive day.

Stick with the octane required. Leaded or unleaded does not matter.  I would run the same fuel and jet accordingly for it.

If you are at drags, if you love to rejet carbs and are good at it, and if you want just a very small bit more power oxygenated fuel requiring a larger jet size MAY perhaps give you more power.  How much, I don't know. Some people just love to tinker...and if that is you...hell than there is nothing wrong with that.

I would say find what works and jet it to run its best and then stick with that fuel and just jet when and if temp or altitude changes require it.   

I have some snake oil that with just 2 drops increases HP by about 40% I will sell you. :)
Logged
If they can't kick start it--THEY CAN'T RIDE IT

Offline

  • Trade Count: (0)
  • Pro Member
  • ********
  • Posts: 858
Re: Race Fuel Question
« Reply #7 on: January 24, 2013, 10:24:51 pm »
Quadman8 is correct about the power potential of high octane fuel.  The octane rating is not a rating on the fuels power potential .  It is a rating on the fuels resistance to detonation. 

I have not found oxygenated race gas to increase the power more than about 1.5% when the jetting is optimized.  I have seen alot of holed and siezed pistons when oxygenated fuel was used and the jets were not right.
Logged

Offline

  • The Most
  • Trade Count: (0)
  • Elite Member
  • **********
  • Posts: 1119
  • Kills: 9007
  • Location: Monahans TX
Re: Race Fuel Question
« Reply #8 on: January 24, 2013, 11:12:48 pm »
I was reading somewhere that the BTU content gets lower the higher you go in octane rating, it's probably so negligible that it doesn't make a pissant difference, but theoretically you'll make more power by running only the amount of octane required to prevent detonation due to more BTU's per gallon of lower octane fuels.

Leaded fuel doesn't matter at all in a 2-stroke, but in a fuel injected engine it can foul up certain O2 sensors.
That reason, and emission requirements, would be the only reasons to stay away from leaded fuels.
Otherwise just save your money and run leaded fuel.

If your engine runs 100 octane, go out and buy some 100LL avgas, it's every bit as consistent as race fuel and cheaper too.
Find it at your local airport.
Logged

Offline

  • Trade Count: (0)
  • Pro Member
  • ********
  • Posts: 858
Re: Race Fuel Question
« Reply #9 on: January 25, 2013, 08:40:23 am »
The BTU content usually goes up as the specific gravity goes down.  Some of the real high octane fuels are real light compared to pump gas that have high aromatic contents.

Gasoline is a cocktail of liquid hydrocarbons that has to have a specific gravity of about .68 to .75 and can produce 17K to 20K BTUs when burned.  These specifications are necessary for our carburetors and fuel injection systems to mix the fuel and air so that it will be combustible.  Basically, if the fuel is outside of these specifications the “jetting” will be too far off for engines that were designed and jetted for gasoline.

The universal BTU content for gasoline regardless of the octane rating, is 17,000 to 20,000 BTU per pound.  If the heat content is outside of this range, it is not gasoline.  If I remember correctly, methanol is about 9,000 Btu/lb, ethanol is about 12,000 Btu/lb and E85 is about 14,000 to 15,000 BTU/lb. 

The heat content of the fuel has nothing to do with its power potential.  The fuel mileage is directly related to the heat content.

An engine processes heat and turns a certain percentage of the heat to crankshaft torque.  About 30 % of the heat is turned into crankshaft power. The remaining 70% of the heat is expelled in the exhaust and dissipated through the cooling system.

An engine has to process the same amount of heat to develop one horsepower regardless what type of fuel it is using.  The heat content of methanol is about 1/2 that of gasoline and is the reason that the fuel mileage for methanol is approximately 1/2 that of gasoline.




Logged
Pages: [1]   Go Up
« previous next »
 

+- Suzuki Quadracer HQ Store Zone

http://www.suzukiquadracerhq.com/index.php?action=store